Food freeze-drying processing lines first freeze the food at very low temperatures. Once frozen, the food enters a vacuum environment, where the ice turns directly into vapor instead of melting into water. Since the drying process happens without prolonged exposure to high temperatures, foods such as strawberries, durian, vegetables, tea powders, and pet food can keep more of their original shape, color, flavor, vitamins, and proteins. To make sure the drying conditions remain suitable as moisture is gradually removed from the products, the freeze-drying process controls both temperature and vacuum throughout the drying cycle. Freeze drying needs continuous cooling to freeze the food and maintain the low temperatures required during the cycle, so the processing setup uses energy-saving refrigeration to reduce power consumption. Heat-recovery technology is also included to lower the overall energy demand of the freeze-drying process.